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Protoporphyrin IX

About: Protoporphyrin IX is a research topic. Over the lifetime, 2250 publications have been published within this topic receiving 65544 citations. The topic is also known as: PpIX.


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Journal ArticleDOI
TL;DR: The penetration of ALA into the skin was almost temperature independent while the following production of PpIX was found to be a strongly temperature‐dependent process.
Abstract: — The temperature dependence of the uptake phase of 5-aminolevulinic acid (ALA) and the following production phase of protoporphyrin IX (PpIX) in normal mouse skin was investigated. A cream containing 20% ALA was topically applied on the skin for 10 min. The amount of ALA-induced PpIX was evaluated by measuring the fluorescence of PpIX from the treated skin. No measurable amount of PpIX was found in the skin immediately after 10 min application of ALA. The penetration of ALA into the skin was almost temperature independent while the following production of PpIX was found to be a strongly temperature-dependent process. Practically no PpIX was formed in the skin as long as skin temperature was kept low (12°C).

33 citations

Journal ArticleDOI
TL;DR: In vivo animal studies reveal that protoporphyrin IX fluorescence is strongly correlated with both MRI and histological staining, confirming that the fluorescence signals are highly specific to tumor cells, and ex vivo spectroscopic studies of excised brain tissues demonstrate that the hand-held spectroscopy device is capable of detecting diffuse tumor margins with low fluorescence contrast that are not detectable with current systems in the operating room.
Abstract: Intraoperative cancer imaging and fluorescence-guided surgery have attracted considerable interest because fluorescence signals can provide real-time guidance to assist a surgeon in differentiating cancerous and normal tissues. Recent advances have led to the clinical use of a natural fluorophore called protoporphyrin IX (PpIX) for image-guided surgical resection of high-grade brain tumors (glioblastomas). However, traditional fluorescence imaging methods have only limited detection sensitivity and identification accuracy and are unable to detect low-grade or diffuse infiltrating gliomas (DIGs). Here we report a low-cost hand-held spectroscopic device that is capable of ultrasensitive detection of protoporphyrin IX fluorescence in vivo, together with intraoperative spectroscopic data obtained from both animal xenografts and human brain tumor specimens. The results indicate that intraoperative spectroscopy is at least 3 orders of magnitude more sensitive than the current surgical microscopes, allowing ultr...

33 citations

Journal ArticleDOI
TL;DR: In this paper, the molecular properties of phenopylate (2,4-dichlorophenyl 1-pyrrolidine carborylate) and 13 of its O-phenyl pyrrolidino-and piperidinocarbamate analogues were correlated with their capacity to inhibit protoporphyrinogen oxidase (Protor), to cause accumulation of protopmorphyrin IX, and to cause herbicidal injury.
Abstract: The molecular properties of phenopylate (2,4-dichlorophenyl 1-pyrrolidinecarborylate) and 13 of its O-phenyl pyrrolidino- and piperidinocarbamate analogues were correlated with their capacity to inhibit protoporphyrinogen oxidase (Protor), to cause accumulation of protoporphyrin IX, and to cause herbicidal injury. All three biological properties correlated well with the van der Waalsvolume, electrophilic superdelocalizability, and energy of the lowest unoccupied molecular orbital. The relationships between biological activities and log P were curvilinear. The activity was mainly centered on the phenyl ring

33 citations

Journal ArticleDOI
TL;DR: Results showed that pH values of the incubation medium containing (5-ALA) below and above pH 7.4 led to a significant decrease in the fluorescence intensity, and depletion of intracellular PPIX was faster in physiological medium than in acid medium.
Abstract: pH-Dependent variations in the fluorescence intensity of 5-aminolaevulinic acid-induced 5-aminolaevulinic acid protoporphyrin IX (PP IX) were compared with the cell viability following light irradiation. The fluorescence intensity was determined by flow cytometry and the cell activity was investigated by a colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay 24 h after photodynamic treatment. The results obtained by fluorescence measurements clearly showed that pH values of the incubation medium containing (5-ALA) below and above pH 7.4 led to a significant decrease in the fluorescence intensity. The viability of cells incubated with 0.6 mM 5-ALA in a medium at pH 6.0 was unaffected on exposure to light at lambda = 635 nm up to 15 J cm-2. However, cells incubated at pH 7.4 (with the other treatment parameters the same) were nearly completely destroyed. In addition, depletion of intracellular PPIX was faster in physiological medium than in acid medium.

33 citations

Journal ArticleDOI
TL;DR: High pressure liquid chromatography was used to demonstrate that chelation of Mg(2+) into protoporphyrin IX precedes methylation in isolated greening etioplasts from cucumber cotyledons.
Abstract: High pressure liquid chromatography was used to demonstrate that chelation of Mg2+ into protoporphyrin IX precedes methylation in isolated greening etioplasts from cucumber (Cucumis sativus L. var. Beit Alpha) cotyledons. Mg-protoporphyrin IX synthesized in vitro from protoporphyrin IX, Mg2+, and ATP or exogenous Mg-protoporphyrin IX could serve as substrates for the methylation step. In either case, S-adenosylmethionine was the methyl donor and could not be replaced by ATP plus methionine.

32 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202383
2022132
202157
202061
201958
201858